Blower fan



P 2, 1969 D. x DENNIS 3,464,622

BLOWER FAN Filed Jan. 25, 1968 11.1 N6 INVENTOR DONALD l. DENNIS United States Patent 3,464,622 BLOWER FAN Donald I. Dennis, Cherokee County, Tex. (R0. Box 418, Jacksonville, Tex. 75766) Filed Jan. 25, 1968, Ser. No. 700,598 Int. Cl. F 04d 29/22, 17/08 US. Cl. 230134 Claims ABSTRACT OF THE DISCLOSURE A squirrel cage type blower fan is described that comprises a central hub for mounting on a shaft, a corrugated disc carried about the axis thereof on the hub and perpendicular to the hub axis, and a plurality of fan blades or vanes supported from the disc adjacent the periphery thereof extending perpendicularly outward therefrom.

Blower units that employ a pair of spaced apart squirrel cage type blowers are commonly used in conjunction with automobile air conditioning units, especially those air conditioning units in which the refrigeration coils or cooling coils are located in a composite unit attached to the under side of the dash panel within the interior of the automobile. The pair of squirrel cage blowers are situated within a blower housing to discharge air across the cooling coils and outward through the unit, and are supported and driven from a shaft of a motor that is mounted between the two blowers, the blowers being mounted on opposite ends of the shaft. This arrangement, of course, requires the production of two types of blower fans for each blower unit, one to turn clockwise and the other to turn counterclockwise. These blowers are generally fabricated from sheet metal by punching out vanes from a disc of the material and bending the vanes to extend perpendicularly outward therefrom leaving a supporting rim from which the vanes protrude and spokes attaching the central portion to the supporting rim. A common denominator of this type of blower fan is that they must generally be dynamically balanced after production and often tend to vibrate and are usually quite noisy. The noise problem is due, in part, to the effect of the edges of the vanes and supporting spokes on the air as the blowers revolve.

It is an object of the present invention to provide a fan that can be readily molded, in one piece, from strong and durable plastics or light metals.

It is a further object to provide a fan having increased efficiency and one that will supply more air for a given motor horsepower rating and size of fan.

It is yet another object to provide a fan that requires no balancing after being produced and one that is quiet in operation.

Still another object is to provide a fan that can be r readily used for either clockwise or counterclockwise rotation.

In accordance with these objects and the principles of this invention a blower fan is provided that comprises a one piece hub mounting a central supporting disc and vanes, that may be readily molded from conventional plastic materials or cast from light-weight metals. The fan is symmetrical about the plane of the supporting disc with the vanes extending outwardly from both faces thereof and thus the fan can simply be reversed and driven from the other side to change from clockwise to counterclockwise drive. Moreover, the supporting disc is corrugated at the central portion thereof and is formed from one solid piece to give greater strength and rigidity in support of the vanes, reducing the possibility of vibration. In addition, supporting annular rings may be pro- "ice vided at either end of the fan attaching at the end of the vanes to increase the rigidity thereof. Moreover, as the vanes are cast rather than stamped the edges may be aerodynamically smoothed and contoured to decrease their agitating eflfect on the air and further decrease the noise of operation of the fan. Also, the fact that the supporting central hub and supporting disc are solid rather than ribbed or vaned decreases the action of the disc against the air decreasing the noise level in operation.

Many other of the objects, features and advantages of the present invention will become readily apparent to those skilled in the art upon reference to the following detailed description of a specific embodiment thereof with reference to the appended claims and accompanying drawings wherein like reference numerals denote like parts and in which:

FIGURE 1 is a perspective view of the fan of this invention;

FIGURE 2 is an end, plan view of the fan shown in FIGURE 1;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 2; and

FIGURE 4 is a detailed view in section and partially broken away taken along line 4--4 in FIGURE 2.

Referring again to FIGURES l and 2 of the drawings a squirrel cage type blower fan in accordance with the principles of the present invention is shown denoted generally by the reference numeral 10. The fan 10- comprises a central hub 12 having an axial opening 14 therethrough for journaling the hub 12 on a shaft (not shown). A split ring arrangement or other suitable means may be provided for holding the hub 12 in place on the shaft and prevent its working off during operation. Extending perpendicularly outward from the hub 12 is a wall or disc 16 which serves to support a plurality of vanes 18 spaced around its periphery with the longitudinal axis of the vanes being parallel to each other and to the axis of the central hub 12. The disc 16 is circular in configuration and is supported on the hub 12 at its axis for rotation therewith.

As shown in FIGURE 3 and in more detail in FIG- URE 4 the supporting disc 16 is a solid piece that is corrugated at the central portion thereof where it contacts the hub 12 with the corrugations diminishing radially outwardly from the hub 12 and terminating in an planar annular rim 20 which carries the vanes 18. As shown, the supporting disc 16 supports the vanes 18 at a point midway their length and thus the hub 12 is centrally disposed in the fan both with relation to the vanes and with relation to the left and right ends of the fan as viewed in FIGURE 2.

In this particular example annular rings 22 and 24 are provided at either end of the fan, fitting in notches 26 in both ends of each of the vanes 18. These rings, 22 and 24, though not absolutely necessary for normal operation of the fan are desirable in that they add rigidity and support to the vanes and aid in preventing flutter or vibration at the high speed at which the fan operates, normally in the order of 2500 rpm. Moreover, due to the support offered by the rings, the vanes 18 may be thinner than what would otherwise be possible and thus offer less resistance to the air.

As shown most clearly in FIGURE 2 each of the vanes 18 may be formed such that they are aerodynamically faired, much as the wings of an airplane, with their leading edges 28 being rounded and their trailing edges 30 being tapered. In addition, the vanes may be curved opposite to the direction of rotation of the fan to provide a more natural path for the escaping air.

The fan of the present invention provides many advantages. Because the central hub 12 and the driving disc 16 are centrally disposed in the fan rather than being placed at one end or the other, the fan can be used for either left hand or right hand drive by simply reversing the side from which the fan is driven. Thus, viewing FIG- URE 2, if the fan were shown from the other side the curvature of the blades 18 would be in the opposite direction for counterclockwise rotation rather than clockwise rotation as shown. Moreover, the fact that the vanes are supported and driven at their centers rather than from one end or the other greatly increased the rigidity and balance of the fan. By thus decreasing the length of the vanes away from the supporting disc 16 and by adding supporting rings 22 and 24 the vanes themselves can be made thinner and smaller to reduce the resistance they present to the air. Resistance may also be reduced by aerodynamic shaping of the vanes. This combined reduction in air resistance not only adds to the efiiciency of the fan, allowing it to produce more air from less horsepower and a smaller size fan, but it also cuts down on the overall noise level of the fan when it is operating. The noise level is further reduced by the corrugated configuration of the supporting disc 16. Were the disc ribbed or spoked, the ribs or spokes would offer resistance to the air crossing the path of rotation of the disc causing air interference noise. Alternatively, were it a flat disc without the attendant ribs or spokes the noise level would be reduced but so would the strength and rigidity of the fan. Thus, by making the disc of one piece the noise level is reduced and by corrugating it strength and rigidity are not sacrificed.

Yet another advantage of the fan is that air entering through the open ends, as shown by arrows 32 and 34, traverses a shorter path than would be the case where the supporting disc 16 placed at one end rather than the center. If the latter were the case and the supporting disc 16 placed at the right end as the fan is viewed in FIG- URE 2, the entering air would only be able to come in through the left hand opening as shown by the arrow 32. Thus, the righthand side of the vanes would have to pull air all the way from the left hand opening, greatly cutting down on the efliciency of that portion of the vanes as compared with the lefthand side of the vanes. Moreover, were the supporting hub 16 placed at the right but with spokes or openings therein to allow air to come in from the right the noise level would be increased due to the action of the spokes against the entering air.

While the fan of this invention has been described with reference to a specific embodiment it is understood that this description is not to be construed in a limiting sense.

.4 Various modifications of the disclosed embodiment as well as other embodiments of the invention, will become apparent to those skilled in the art upon reference to the foregoing specification and appended claims. It is therefore contemplated that the appended claims will cover such modifications or embodiments as fall within the true scope of this invention.

What is claimed is:

1. A blower fan comprising:

(a) a central hub for mounting on a shaft,

(b) a disc carried about the axis thereof on said hub with the plane of said disc being perpendicular to the axis of said hub,

(c) said disc being of corrugated structure at the hub thereof, the corrugations extending radially from the hub and diminishing radially outwardly from said hub,

(d) a plurality of fan vanes supported from both faces of said disc adjacent the periphery thereof and extending outwardly in opposite directions perpendicular to said plane of said disc.

2. A blower fan as defined in claim 1 wherein said fan vanes are spaced around the periphery of said disc.

3. A blower fan as defined in claim 1 wherein said fan vanes are curved in a plane perpendicular to the plane of rotation of said disc and are generally inclined to a radius of said disc passing through said vanes for causing a flow of air upon rotation of said disc.

4. A- blower fan as defined in claim 1 wherein the periphery of said disc comprises a planar, annular rim from which said fan vanes are supported and wherein said corrugations terminate at said annular rim.

5. A blower fan as defined in claim 1 also including an annular ring attached to and supporting the outward ends of said fan vanes at each end of said blower fan.

References Cited UNITED STATES PATENTS 2,652,190 9/ 1953 Meltzer et a1. 2,549,208 5/1951 Kice 230-1345 2,991,004 7/1961 Denbo et a1. 3,021,049 2/ 1962 Settle.

FOREIGN PATENTS 156,976 1/1921 Great Britain.

HENRY F. RADUAZO, Primary Examiner 

